Die



June 9, 1936. l PETERQSION DIE Filed June 25, 1934 3 Sheets-Sheet 1 r I INVENTQR PE far 7616 871; 032

ATTORNEYS Patented June 9, 1936 UNITED STATES PATENT OFFICE DIE poration of Ohio Application June 25, 1934, Serial No. 732,370

11 Claims.

The invention relates-tothe die forming of sheet metal and has for its object the obtaining of an apparatus which has certain advantages over and avoids certain defects of constructions heretofore used for the same purpose. More specifically, it is the object to obtain a construction of cooperating dies which in use minimize the depth of draw in the sheet metal blank, which avoids the forming of die marks, the scratching or the wrinkling of the metal, and which permits of fashioning under-cut forms and the embossing of portions thereof, all in a single operation. To this end the invention consists in the construction as hereinafter set forth.

While my apparatus may be used for the forming of many different pressed sheet metal structures, I shall specifically describe its use for the formation of automobile fenders. In the present state of the art it is customary to providesuch fenders with side or skirt portions extending a considerable distance down from the fender top. These portions are also embossed or beaded both for the purpose of ornament and to increase the stiffness of the structure. Such shapes are difficult to form from sheet metal blanks without in- VOIViIlg objectionable deep drawing .of the .metal or the fashioning of the structure by successive die operations. There is also danger of forming wrinkles in the blank which must be subsequently ironed out and it is difficult to avoid the formin of scratches or die marks.

These difficulties I have overcome by. the construction of dies which first press themetal at an oblique angle to the original plane of the blank and second, in the same operation press undercut portions.

In the drawings:

Fig. l is a longitudinal section of a specific form of fender which may be fashioned by my improved dies;

Fig. 2 is a plan view thereof;

Fig. 3 is an end elevation;

Fig. 4 isa plan view of the female die;

Fig 5 is a longitudinal section on line ,5-5, Fig. 4, showing the female die and cooperatingclamping die;

Fig. 6 is a view similar to Fig. 4 showing the male die partly'broken away to illustrate thesliding connection between the same and its actuating plunger;

Figs. '7 and 8 are cross sections respectively on lines 1-! and 8--8, Fig. 6;

Fig. 9 is a cross section on line 9-9, Fig. 6, showing in dotted and full lines respectively the initial position and the final position ,of dies,

Fig. 10 is a similar viewillustrating an intermediate position;

Fig. 11 is across section on line Il-l'l, Fig. .6.

The specific form of fender which I have illustrated as being fashioned by my improved die is shown in Figs. 1 to 3 inclusive, in which Ais the front portion which is curved longitudinally substantially concentric with the axis of the wheel and which is also curved in cross section. A is theportion extending longitudinally from the portion A to the running board and A isa deep skirt depending from the outer side of this portion. This skirt has a beading A extending longitudinally near its lower .edge and which continues around the lower edge of the portion A as indicated at A Such a form if fashioned by dies operating perpendicular to the original plane -.of the blank would require an exceedingly deep drawing operation with the consequent .dimculties of over-stressing and possibly fracturing .the metal or the forming of wrinkles and die marks in the structure which must be subsequently ironed out. Also it would be impossible to form the embossing or beading A and A in the same operation by a die moving through arectilinear path. To avoid the deep drawing operation I so fashion the dies that the blank as first clamped extends at an .oblique angle to the initial direction of movement of the formingdie. This, however, necessitates under-cut portions in the completely fashioned structure, meaning by this shapes which the forming die cannot fashion by a rectilinear movement. I have therefore devised .a construction in which the male ,die in its final operation moves at an angle to the direction 'of its initial movement and which therefore provides clearance for these under-.cutportions. This also permits of forming the bead or other embossing .during the final portion of the movement so that there is no necessity of a subsequent die operation.

In detail, B is the holder vfor the female dies and also for the marginal Jolank clamping dies. This holder has a rectangular recess 0 in which may be placed exchangeable dies D fashioned to correspond to the particular shape desired. On opposite sides of the recessC are portions E which are arranged in a general plane extending at .an

oblique angle to the base of the member B and at F to receive the ribs E Thusa sheet metal blank placed between the members F and B will be marginally clamped upon opposite sides of the recess C in which the female die is located. G is the male die which extends through a central recess in the clamping die holder F, said recess providing sufficient clearance for lateral movement as well as longitudinal movement of said die G. All of these die members B, F and G are adapted for use on any standard form of press, the member B being supported upon the bed and the members F and G being secured to and operated by separately actuated plungers. construction of this press is not essential to the present invention it is believed unnecessary to' illustrate the same.

To form the fender it is necessary that the male die member G should first be actuated in a direction perpendicular to the base of the member B but at an oblique angle to the general plane of the blank; second, that during this forming operation the direction of movement ofthe member G should be changed so that it can enter into the under-cut portions of the die D as for instance as shown at D, Figs. 9 and 10, and at D Fig. 5. It will be noted that this requires a lateral movement of the die G in a direction which is oblique to both the longitudinal and transverse planes of the dies. Thus the under-cut portion D is entered by the movement in the longitudinal plane and the under-cut portion D by a movement in the transverse plane. Such movement is accomplished by slidably mounting the die G on the under face of a member H which latter is rigidly attached to its actuating plunger on the press (not shown) The attachment between the dies G and the member H is formed by T-shaped slides I extending obliquely along the member G, being secured thereto by bolts I, together with slides J secured to the member H by the bolts J. These cooperating slides hold the upper face of the member G in contact with the under face of the member H and'confine its lateral movement to the direction of the slides I and J. Normally, the member G is held in a position to the left, Fig. 9, by the resilient pressure of a spring K arranged in a recess between the members G and H, one end of said spring abutting against a shoulder K on the member G and the other end against a flange K depending from the member H. In this position the die G can move downward into the die D without interference therewith. The lateral movement of the die G is effected by cams which as specifically shown comprise oblique faces L and L on the left side of the member G, Fig. 9, and cooperating oblique faces M, M, M on the member F. These cam surfaces may be formed on inserts which are mounted respectively in the members 'G and F. Themember G is also provided with a cam or oblique face N to the left, Fig. 5, which cooperates with oblique faces 0 and O on the member F to move the die G longitudinally at the same time that it is moved laterally by the cams L, M, L, M. Thus the result of these two movements is the oblique movement in the direction permitted by the slides I and J.

With the construction above described, the operation of the cooperating dies will be apparent but briefly is as follows: In the initial position the clamping dies F, F are separated from the cooperating clamping dies E and E so as to per- As the-- the marginal portion of the blank by the ribs E entering the recesses F The die G then descends in a vertical direction indicated by dotted lines P, Fig. 9, drawing the metal between the clamped margins until it assumes the form shown in Fig. 10. The oblique surfaces L, L and N then engage the cooperating surfaces M, M, M 0, 0, moving the die G laterally during its further descent or as indicated by the dotted line at P, Fig. 9. Thus the cooperating form faces on the die G and the under-cut portions of the die D will be pressed together so as to fashion the blank therebetween. The return movement is the reverse of that described, the die G first ascends in the direction of the line P and then vertically along the line P. The spring K furnishes the necessary pressure for effecting the lateral movement of the die G during its upward movement.

Where the structure to be formed is of the character of the fender shown in Figures 1 to 3 of the drawings, the undercut portions of the female die are arranged both at the en and at the side. The male die is also provided with projecting portions for engaging both the end and side undercut portions. Therefore, there is necessity of moving the male die after initial entrance of the same in a direction which will bring both of these projecting portions into engagement with the corresponding undercut portions. This is accomplished in the specific construction shown by arranging the cooperating slides I and J at an oblique angle with respect to the longitudinal and transverse axes of the fender. In general, the dies must be so designed that where the female die member has undercuts in portions which extend at an angle to each other and the male die member is provided with corresponding projecting portions the initial movement must be in a direction to permit of inserting the male diemember within the cooperating die and the change of direction must be such as to bring all of the projecting portions into the corresponding recesses.

What I claim as my invention is:

1. Sheet metal forming means comprising cooperating relatively movable die members, a pair of said members being adapted to marginally clamp the sheet metal blank, a third die member of rigid form movable relative to the other two in a direction oblique to the plane of the clamped blank, and means operating during such relative movement after initial engagement with the blank for changing the direction of said movement.

2. Sheet metal forming means comprising a die member having a supporting base, a clamping face at an oblique angle to said supporting base and an undercut recess in said clamping face, a cooperating die member for marginally clamping a sheet metal blank to said face and to extend over said recess, a third rigid die member movable in a direction perpendicular to said supporting base to press said blank into said recess and means operating after initial movement of said third die member for laterally moving the same in the undercut portion of said recess.

.3. Sheet metal forming means comprising a die member having a base portion and a clamping face at an oblique angle to said base portion pro vided with a fashioned recess therein, a member for marginally clamping a sheet metal blank to said oblique face so as to extend across said recess, a rigid die member initially movable in a direction perpendicular to said base to press said blank into said recess, the latter being provided with an under-cut portion with respect to said direction of movement and means operating after the entrance of said third die member into said recess for changing the direction of travel to engage said under-cut portion.

4. Sheet metal forming means comprising a plurality of relatively movable die members, a pair thereof being provided with cooperating clamping faces oblique to the direction of relative movement to marginally clamp a sheet metal blank therebetween, one of said members having a fashioned recess with a portion under-cut with respect to said direction of movement, a third rigid die member movable through a central recess in the other of said clamping members to press the sheet metal into the fashioned recess of the first clamping member, and cams engaging said third die member during its inward movement to force the same laterally into engagement with the under-cut portion of said fashioned recess.

5. Sheet metal forming means comprising a plurality of elatively movable die members, a pair thereof being provided with clamping faces in a plane oblique to the direction of relative movement, one of said members having a fashioned recess with a portion under-cut with respect to the direction of movement and the other of said clamping members being centrally recessed and provided with a cam face on one side thereof, a third rigid die member movable through said central recess in the second die member and into engagement with said fashioned recess, a plunger for moving said last mentioned die member, connecting means between said die member and plunger permitting relative lateral movement thereof, resilient means for yieldably holding said die member at one limit of its lateral movement, and a bearing on said die member engageable during the movement thereof with said cam to compel a lateral movement against the pressure of said resilient means and to engage said die member with the under-cut portion of said fashioned recess.

6. Sheet metal forming means comprising respectively rigid male and female dies, the one having an undercut portion and the other a laterally projecting portion for engagement therewith, means for holding a sheet metal blank between said dies, means for relatively moving said dies initially in a direction to permit of engagement and to effect the preliminary drawing and forming of the sheet metal blank and means for subsequently changing the direction of relative movement to engage the projecting portion of the one with the undercut portion of the other and to complete the forming of the article.

7. Sheet metal forming means comprising respectively rigid male and female dies, one having an undercut portion and. the other a laterally projecting portion for engagement therewith, means for holding a sheet metal blank between said dies, means for relatively moving said dies in a direction oblique to the plane of said blank and so as to clear the projecting portions from said undercut portions to effect a preliminary drawing and forming of the blank, and means subsequently operating to change the direction of relative movement of said dies to press the laterally projecting portion into the undercut portion and to complete the forming.

8. Means for completely forming an article in a single operation comprising respectively rigid male and female dies, the one having an undercut portion and the other a laterally projecting portion for engagement therewith, means for holding a sheet metal blank between said dies, means for relatively moving said dies in a direction oblique to the plane of said blank and so as to clear said projecting portion from said undercut portion to effect a preliminary drawing and forming, and means operating during the continued relative movement of said dies for changing the direction of relative movement thereof to press said laterally projecting portion into engagement with said undercut portion and to thereby complete the forming operation.

9. Means for forming sheet metal blanks into fenders and the like comprising respectively rigid male and female dies, the one having an undercut portion and the other a laterally projecting portion for engagement therewith, means for holding a sheet metal blank between said dies, means for relatively moving said dies initially in a direction oblique to the plane of said blank and so as to clear the projecting portion from the undercut portion to effect a preliminary drawing and forming of the blank, and means operating during the continued relative movement of said die members for changing the direction of relative movement thereof to press said laterally projecting portion into engagement with said undercut portion and to thereby complete the forming.

10. Sheet metal forming means comprising respectively rigid male and female dies, the one having undercuts in portions which are at an angle to each other and the other laterally projecting portions for engagement therewith, means for holding a sheet metal blank between said dies, means for relatively moving said dies initially in a direction to permit of engagement and to effect the preliminary drawing and forming of the sheet metal blank, and means for subsequently changing the direction of relative movement to engage the projecting portions of the one with the undercuts in the angling portions of the other.

11. Sheet metal forming means comprising a plurality of relatively movable members, one of said members being provided with a recess having a marginal blank clamping portion, another member cooperating with said marginal portion to clamp a sheet metal blank extending across said recess, and a third member movable through said second member into said recess, said recess having undercuts formed in side portions thereof which are at an angle to each other and said third member having lateral projections therefrom corresponding to said undercut portions, means for relatively moving said first and second members to clamp the blank, and means for relatively moving said third member with respect to said first and second members initially in a direction to clear said projecting portions while entering said recess and subsequently in a direction to engage said projecting portions with the undercut portions on the angling sides of said recess.

PETER PETERSON. 

